Pinellas is under alert for West Nile

Six more counties, including Pinellas, Pasco and Hernando, have been placed on a medical alert for West Nile virus.

Those three counties, plus Alachua, Palm Beach and Putnam, were added to 18 others already on alert. Health care workers in those counties have been advised to watch for symptoms of the virus.

Florida Department of Health officials added the counties to the medical alert after detecting West Nile virus in more birds and other animals.

"The message is simple but important," Dr. John Agwunobi, secretary of the health department, said in a press release Monday. "People must continue to take precautionary measures to avoid being bitten by mosquitoes."

Although less than half of Florida's counties are on medical alert this year, compared to a statewide alert last year, state health officials have previously warned that people throughout the state are at risk, and health officials predict the disease will eventually spread all over Florida.

Six humans have been diagnosed with West Nile virus so far this year. None has died.

People are urged to guard against mosquito bites, mainly by wearing long pants, long-sleeved shirts, socks and shoes at dawn and dusk, when mosquitoes are most active. Officials advise using mosquito repellent when outdoors and eliminating pools of standing water that can be mosquito breeding grounds.